Ellipse or circle compass



Nov. 29, 1938. v 1 vWEQKERT 2,138,414

ELLIPSE OR CIRCLE COMPASS Filed March 4, 1936 3 Sheets-Sheet l 'A h Anscrkerzz Iraqenzbr- A Homey Nov. 29`7 1938.

J. WECKERT 2,138,414

ELLIPSE OR CIRCLE COMPASS Filed March 4, 1956 3 Sheets-Sheet 2 llllhhllhhhhh hhhhhl hhhlnf i W Nov. 29, 1938.l- .1 WECKERT ELLIPSE OR CIRCLE COMPASS 5 sheets-sheet 3 Filed March 4, 195e ]se/b Wecker? A Homey Patented Nov. 29, 1938 UNITED STATES EFATENT OFFICE v ELLIPSE OR CIRCLE COMPASS Joseph Weckert, Cloquet, Minn.

Application March 4, 1936, Serial No. 67,122

12 Claims.

My invention relates generally to an instrument for drawing and scribing circular, oval, and elliptical figures or, curves, and an important object of the invention is to provide an instrument of this character which is readily accurately adjustable and which is capable of producing substantially perfect lines and figures.

Anothe-r important object of the invention is to provide a mechanically superior device of the character indicated which can at low cost be constructed in a long wearing and rugged form.

Another important object of my invention is to provide an instrument of the character indicated above which will remain in an adjusted position until re-adjusted.

Other important objects of my invention will be apparent from a reading of the following description in connection with the drawings, wherein for purposes of illustration I have shown a preferred embodiment of my invention.

In the drawings:-

Figure l is a general side elevational view of the embodiment showing the same in an operative position.

Figure 2 is a transverse vertical sectional view taken through the upper part of Figure l.,

Figure 3 is a horizontal sectional view taken through the cord reel.

Figure 4 is a transverse vertical sectional view taken through the joint structure of one oi the connecting links.

Figure 5 is a horizontal sectional view taken through Figure l approximately on the line 55.

Figure 6 is a horizontal sectional view taken through Figure 1 approximately on the line @-5 and looking downwardly.

Figure '7 is a transverse vertical sectional view taken through the main arm of the embodiment.

Figure 8 is a top plan view showing diagrammatically an adjusted operative position of the device showing the same completing a wide ellipse, and showing the positions which the relatively stationary legs would occupy in scribing a relatively narrow ellipse. Figure 9 is ahorizontal sectional view taken through Figure 7 approximately on the line S-. Figure 10 is a horizontal sectionalview taken through Figure 7 approximately on the line Ill-IU.

Figure l1 is an elevational view of a portion of the main arm looking at the reverse side thereof from that shownin Figure 1.

Referring in detail the drawings, the numeral y 5 generally designates the adjusting screw which has a smooth and pointed lower end 6 which passes through a sleeve 'l and said sleeve has diametrically opposed pairs of ears 9 which contain pivots I0 and ll which pivot the lower ends of the connecting links i 2 and i3 to the 5v vsaid sleeve and which have their upper ends pivoted as indicated by the numerals -l and l5 between the pairs of ears I6 and l1 extending inwardly from the upper part of the relatively stationary legs I3 and I9.

The stationary leg I8 is tubular in form and has extending from its lower end a surface engaging point l8a. At the outer side of the leg I8 and slightly elevated above the pair of ears l5 is the pair of ears 20 between which is pivoted as indicated by the numeral 2| the oord reel 22 on which the cord 23 is wound, the cord passing downwardly and into the interior of the leg through an opening 24 and emerging again through an opening 25, near the point 18a. Above the ears 2li the upper arms portion 26 inclines inwardly and is provided with ears 2l and 28 which are traversed by screws 29 and 30, the inner ends of which are socketed in diametrically opposite sides of a sleeve 3| which has a smooth bore 32 turning on the screw 5, and a rest flange 33 on its upper end to be engaged by the lower end of a portion of the main swingable arm to be described.

The screws 29 and 3l! also traverse ears 34 and 35 on the inwardly inclined upper part 26 of the leg I9, and a locking nut 3S is threaded on the outer part of the screw 29 to clamp the. respective ears on the upper ends of the legs I8 and E9 together and against the outside of the sleeve 3l, so as to lock these legs in adjusted positions relative to each other and relative to the screw 5.

Turning on the screw 5 above the sleeve 3| is the cylindrical portion 3l of the main swingable arm which is provided with a smooth bore 33 engaging the screw 5 and with a horizontal lateral arm 39 containing a pair of ears 40, and a lateral upwardly and outwardly inclining arm ll which is provided with a pair of ears 42. Both the ears l2 and the ears 4B are provided with respective pivot accommodating openings 43 and 44 which receive the pivots 45 and 46, respectively. A thumbscrew traversing the cylindrical portion 31 can be adjusted to lock the cylindrical portion 37 in place.

The upper part of the cylindrical portion 31 is provided with a socket 41 whose mouth is provided with a radially inwardly extending retaining ange 48 which rotatably confines a laterally enlarged head 4-9 on the lower end of the adjusting nut 5U which bears its lower end against the top of the ilange 48 as clearly shown in Figure 2.

The nut 59 is threaded on the screw 5 and above it is threaded on the screw 5 a lock nut 5| which is designed to jam against the 'top of the nut 56 and lock the adjustment of the nut 5I),k whereby the position of elevation of the cylindrical part 51 of the main swingable arm .is determined on the screw 5.

The main swingable arm which is generally designated 52 comprises a straight tubular portion 53 which is open at its lower end and merges at its upper end into the attened triangular part 54 which has a reduced vertical extension `55 which itself has an upwardly and outwardly inclining arm 56 which has a ange 51 at its upper end through which is threaded the tension adjusting screw 58 which has thereon a lock nut 59 for engaging the top of the ange 51 to lock the screw in place after adjustment. The screw has attached to its lower end as indicated by the numeral 66 the upper end of a contracting spring 6I which has its lower end fixed to a lug 62 on the lower end of the cylindrical part 31. The greatest length of the portions 54 and 55 is on a line which leans away from the axis of the tubeV 52 in one direction, while the arm 56 leans more acutely in the opposite direction, butin the same plane in which the parts 54 and 55 lie.

The pivot 45 on the arm 39 engages the hole 63 on the part 54, which part 4is located between the ears 40, of the arm 39, while another pivot 64 engages the hole 65 in the upper end of the part 55, and the pivot 64 engages the approximate middle of a beam 66 which has in its left hand end an elongated double curved slot 66' in which the thumbscrew equipped pivot 46 works. The pivot 46 is mounted on the upper part of the arm 42 on the cylindrical part 31. The double curved slot 66 includes from right to left an upwardly and laterally curving part merging into a laterallyy outwardly and downwardly curving part. When the desired adjustment of the pivot 46 along this slot is obtained the thumbscrew may be tightened to hold the adjustment. The beam 66 has in the opposite or right hand and offset end a pivot 61 traversing the bar 68 in which is adjustably threaded the connecting rod 69 which has its lower end threaded and fastened with a lock nut indicated at 19 to a slide 'I2 which is slidably mounted on the main arm 52.

o Reference to Figure 5 shows the construction of the slide 12 which has the screw 13 traversing a slot arranged longitudinally through the side of the tube 52 and threaded as indicated by the numeral 14 into the side of an inner tube 16 which has a part extending below the lower end of the tube 53 as clearly shown in Figures l and '1. This arrangement makes the tube 16 slidable relative to the tube 53 responsive to the movement of the slide 12 as it is worked by the connecting rod 69 which is, in turn, operated by the beam 66. l

The lower part of the tube 16 has inserted therein a suitable scriber 11 which may be in the form of a plain point or in the form of a pen or pencil.

Ball bearings 18 are seated in recesses in the sides of the upper part of the tube 16 while other ball bearings 19 are seated in recesses in the sides of the lower part of the tube 53, so that the tube 16 is both rotatably and slidably supported in spaced concentric relation to and within the tube 53, as clearly indicated in Figures 9 and l0.

To one side of the lower part of the tube 16 is mounted a V-shape bracket one arm of which carries a rectangular member 8| whichY has at its radially inward end a three-quarter circular hook or eye 82 whose free end 83 terminates in close spaced relation Vto an angulated portion 84 of the member 8|, this arrangement being for ready reception of the cord 29 and capable of retaining the same while the cord moves through the eye during the operation of the swingable arm 52.

The reel. 22 has its manually operated drum 2| mounted in the ears 20 on the leg I8 in such a way that sufficient retaining friction is exerted on the drum to retain the same in a selected rotated pos-ition to resist unwinding of the cord 23 except when the drum is manually operated. The cord 23 emerging into two strands 35 and 85 from the opening 25 in the lower end of the leg I8, has the strand 85 passed through an eye 81 on the side of the lower part of the leg I9 and the strand 86 is free of the eye 81, these strands becoming one in passing through and in the eye 82 as shown in Figure 1.

A thumbscrew 88 is provided for tightening the pen or pencil 11 used in the lower end of the tube 16.

When it is desired to use the device to draw an elliptical iigure, the nut 36 is loosened and the legs I8 and I9 adjusted the proper distance apart and then the nut 56 tightened. At this time Y screw shaft 5 is adjusted so as to raise its pointed end above the pointed ends of the legs I8 and I9. The nut 55 is turned to adjust the member 31 so that the pencil point 11 is about one-eighth of an inch higher than the points of legs I8 and I9. The nut 46 must be loose to permit the arm 52 to swing outwardly under the `action of the spring 6I though, of course, this outward swinging movement is limited by the cord which passes around the three parts I3, I9 and 16. The arm 52 should be brought close to the leg I8 in starting the operation and then by moving the arm 52, using the member 8| as a handle, the iigures can be drawn. legs I8 and I9 and the amount of cord passing around the three parts I8, I9 and 16 ovals of diierent sizes and shapes can be drawn as well as curves.

When it is desired to use the device to draw a circle the screw shaftv' is adjusted through sleeves 1 and 3i and member 31 until its point is below the points of the legs I8 and I9 and the member 31 raised or lowered by turning nut 5|! until the pencil point 11 is about even with the point of the screw shaft 5. If the cord is allowed to remain in the eye 82 of the member 16 while the parts are being adjusted the adjustments are more easily made. Then the cordr is removed from the eye 82 and the arm 52 is permitted to be swung out by the spring 6| to the desired position. Then the nut 46 is tightened as is the screw. Then the parts are all held in adjusted position and the circle can be drawn by simply rotating the device on the pointed end of the screw shaft 5, the pencil 11 making the circle. The legs I8 and I9 can be used as a divider and if desired by lowering screw shaft 5 until its point is below the points of legs I8 and I9 this member 5 and the pencil 11 can be used as a1 divider, the arm 52 being By adjusting they held in adjusted position by tightening the nut 46.

In drawing ovals and curves it is advisable to hold the device in a vertical position by grasping the upper end of the screw shaft 5 and then grasp the handle 8l and turn the arm 52 which, of course, imparts rotary movement to the tubular part 31 which rotates around the shaft 5. In starting out the arm 52 should be near the leg I8.

It will be seen that as the arm 52 is moved outwardly or inwardly the slot 66' and the bolt 46 passing through it will cause the pencil carrying part 16 to move outwardly and inwardly and thus cause the pencil to remain on the surface being drawn upon.

What is claimed is:-

1. An instrument of the character described comprising a main swingable leg having a scribing poit, and a relatively stationary support on which said main leg is swingably mounted, said support comprising a central rod designed to assume a perpendicular position relative to the work, a pair of relatively stationary legs each having a point equipped lower end, rst means pivotally connecting the upper ends of the stationary legs together and to said central rod, a vertically adjustable member on said central rod above said rst means, and second means rotatably mounting said main leg on said vertically adjustable member for rotation on the axis of said central rod.

2. An instrument of the character described comprising a main swingable leg having a scribing point, and a relatively stationary support on which said main leg is swingably mounted, said support comprising a central rod designed for perpendicular disposition relative to the work, a pair of relatively stationary legs each having a point equipped lower end, rst means pivotally connecting the upper ends of the stationary legs together and mounting the same on said central rod, a vertically adjustable member on said rod above said rst means and on which said main swingable leg is mounted, and spring tensioning means operating between said main leg and said vertically adjustable member, said main leg being arranged to swing on the axis of said central rod.

3. An instrument of the character described comprising a main swingable leg having a scribing point, and a relatively stationary support on which said main leg is swingably mounted, said support comprising a central rod arranged for perpendicular disposition relative to the work, a pair of relatively stationary legs each having a point equipped lower end, first means pivotally connecting the upper ends of the stationary legs together and mounting the same on said central rod, a vertically adjustable member on said rod and carrying said main swingable leg for swinging on the axis of said rod, bracket means on said vertically adjustable member, said main leg including a rockable beam pivoted thereto, a pivotal and sliding connection between said bracket means and said beam, and a xed pivotal connection between said bracket means and said main swingable leg,

4. An instrument of the character described comprising a main swingable leg having a scribing point, and a relatively stationary support on which said main leg is swingably mounted, said support comprising a central rod arranged for perpendicular disposition relative to the work, a pair of relatively stationary legs each having a point` equipped lower end for engagement with the. work, iirst means pivotally connecting the upper ends of the stationary legs together and mountingV the same on said central rod, a rotatable vertically adjustable member on said rod, said member including bracket means, said main leg comprising a main portion and a beam pivoted thereto, a pivotal and sliding connection between said beam and said bracket means, a xed pivotal connection between said main portion and said bracket means, said main portion of said main leg including a longitudinally slidable scribing member extending from the lower end thereof, and a connection rod operatively connected between said scribing member and said beam.

5. An instrument of the character described comprising a main swingable leg having a scribing point engageable with the work, and a relatively stationary support on which said main leg is swingably mounted, said support comprising a central threaded rod arranged for perpendicular disposition relative to the work, a pair of relatively stationary legs each having a point equipped lower end, rst means pivotally connecting the upper ends of the stationary legs together and mounting the same on said central rod, a vertically adjustable member on said rod above said rst means, said member comprising an unthreaded rotatable element on which said main leg is mounted and a threaded element operatively connected to said unthreaded elements being free to rotate relative to each other.

6. An instrument of the character described comprising a main swingable leg having a scribing point engageable with the work, and a relatively stationary support on which said main leg is swingably mounted, said support comprising a central rod arranged for perpendicular disposition relative to the work, a pair of relatively stationary legs each having a point equipped lower end, rst means pivotally connecting the upper ends of the stationary legs together and mounting the same on said central rod, a vertically adjustable member rotatably mounted on said rod and carrying said main swingable leg, an extensible scriber on the lower end of said main leg, one of said stationary legs including a reel, rod wound on said reel and strung between said one leg to the remaining stationary leg and to said extensible scriber on the lower end of said main swingable leg.

7. An instrument of the class described comprising a central shaft, a sleeve on the shaft, a

pair of legs having their upper ends pivoted to i the sleeve whereby said legs can be moved toward and away from each other, means for locking the legs in adjusted position, a frame slidably arranged on the upper part of the shaft, a scribing leg pivoted to the frame, spring means for moving the last-mentioned leg outwardly, a reel carried by one of the first-mentioned legs, a cord on the reel, guide means for the cord on said one leg, a portion of the cord forming a loop for passing around the lower ends of the three legs, a point carrying member slidably arranged in the scribing leg and means for sliding the member to keep the point on a surface on which the device rests as the scribing leg is swung outwardly or inwardly.

8. An instrument of the class described comprising a central shaft, a sleeve on the shaft, a pair of legs having their upper ends pivoted to the sleeve whereby said legs can be moved toward and away from each other, means for locking the legs in adjusted position, a frame slidably arranged on the upper part of the shaft, a scribing leg pivoted to the frame, spring means for moving the last-mentioned leg outwardly, a reel carried by one of the first-mentioned legs, a cord on the reel, guide means for the oord on said one leg, a portion of the cord forming a loop for passig around the lower ends of the three legs, a point carrying member slidably arranged in the scribing leg and means for sliding the member to keep the point on a surface on which the device rests as the scribing leg is swung outwardly or inwardly, said means including a lever pivoted intermediate its ends to the frame and having a curved slot in one end thereof, a set screw passing through the slot into a part of the frame and means for connecting the other end of the lever to the sliding member.

9. An instrument of the class described comprising a threaded shaft having a pointed lower end, a sleeve having a smooth bore through which the shaft passes, a pair of arms having their upper ends pivoted to the sleeve, means for locking the arms in adjusted position, a frame including a tubular part having a smooth bore through which the upper end of the shaft passes, a nut rotatably connected with the tubular part and threaded on the shaft, a lock nut on the lastmentioned nut, a scribing leg pivotally connected with a part of the frame for swinging movement toward and away from the other legs, spring means for normally moving the scribing leg outwardly, a point carrying member slidably arranged in the scribing leg, a lever pivoted intermediate its .ends to the frame and having a curved slot in one end portion, a set screw passing through the slot into a part of the frame for moving the lever on its pivot as the scribing arm moves inwardly or outwardly, the screw holding the lever against movement when the screw is tightened and a link connecting the other end of the lever with the sliding member in the scribing leg.

1G. An instrument 'of the class described comprising a vthreaded shaft having a pointed lower end, a sleeve having a smooth bore through which ythe shaft passes, a pair of arms having their lupper ends pivoted to the sleeve, means for locking the arms in adjusted position, a frame including a tubular part having a smooth bore through which the other end of the shaft passes, a nut rotatably connected with the tubular part and threaded on the shaft, a lock nut on the last-mentioned nut, a scribing leg pivotally connected with a part of the frame for swinging movement toward and away from the upper legs, spring means for normally moving the scribing leg outwardly, a point carrying member slidably arranged in the scribing leg, a lever pivoted intermediate its ends to the frame and having a curved slot in one end portion, a set screw passing through the slot into a part of the frame for moving the lever on its pivot as the scribing arm moves inwardly and outwardly, the screw holding the lever against movement when the screw is tightened and a link connecting the other end of the lever with the sliding member inthe scribing leg, a member having a bore through which the shaft passes and links pivotally connected to said member and also pivotally connected to the first-mentioned legs.

11. An instrument of the class described comprising a threaded shaft having a pointed lower end, a sleeve having a smooth bore through which the shaft passes, a pair of arms having their upper ends pivoted to the sleeve, means for locking the arms in adjusted position, a frame including a tubular part having a smooth bore through which the upper end of the shaft passes, a nut rotatably connected with the tubular part and threaded on the shaft, a lock nut on the last-mentioned nut, a scribing leg pivotally connected with a part of the frame for swinging movement toward and away from the other legs, spring means for normally moving the scribing leg outwardly, a point carrying member slidably arranged in the scribing leg, a lever pivoted intermediate its ends to the frame and having a curved slot in one end portion, a set screwpassing through the slot into a part of the frame for moving the lever on its pivot as the scribing arm moves inwardly and outwardly, the screw holding the lever against movement when the screw is tightened and a link connecting the other end of the lever with the sliding member in the scribing leg, and means for fastening the tubular part vof the frame to the shaft.

l2. An instrument of the class described comprising a threaded shaft having a pointed lower end, a sleeve havingv a smooth bore through which the shaft passes, a pair of arms having their upper ends pivoted to the sleeve, meansV for locking the arms in adjusted position, a frame including a tubular part having a smooth bore through which the upper end of the shaft passes, a nut rotatably connected with the tubular part and threaded on the shaft, a lock nut on the lastmentioned nut, a scribing leg pivotally connected with a part of the frame for swinging movement toward and awayfrom the'other legs, spring means for normally moving the scribing leg outwardly, a point carrying member slidably arranged in the scribing leg, a lever pivoted intermediate its ends to the frame and having a curved slot in one end portion, a set screw passing through the slot into a part of the frame for moving the lever on its pivot asthe scribing arm moves inwardly and outwardly, the screw holding the lever against movement when the screw is tightened and a link connecting the other end of the lever with the sliding member in the scribing leg, an adjustable flexible member forme ing a loop around the lower ends of the three legs.

JOSEPH WECKERT. 

